NIRI Update: mechanisms examined and fixed

The stepper motor on the pupil wheel failed. The stepper motor was replaced
with a spare, and the mechanism thoroughly checked. No other damage was
found, and the wheel is working again.

The OIWFS gimbal mirror had in fact run through a limit switch without stopping.
The switch was damaged, as were some of the fragile linkages in the gear train.
The damaged parts were replaced with spares, and the gears carefully inspected.
The mechanical parts of the mechanism are working once again.

The electronics associated with the OIWFS gimbal mirror sensors and limit
switches were examined. One cable connector inside the external electronics
cabinet was destroyed, probably by a short between a power supply and the
ground shield on the cable. The cable and connector were replaced and the
electronics tested. The short was almost certainly the cause of the sensor
failure that led to the OIWFS gimbal mirror running through its limit switch.

NIRI will be cooled again in the lab during the coming week. We will then enter
a period of mechanism testing and instrument engineering in support of Altair
commissioning in mid-November. After the lab testing, the NIRI mechanisms will be
left in position for the Altair commissioning.

If all goes well with the lab testing, instrument engineering, and Altair
commissioning, we may be able to resume queue observations sometime in December.
No additional Phase II submisions will therefore be needed until the first of
December. Please watch these pages for more information on the results of
the testing and plans for resuming queue observations.